Sekihara H, Yazaki Y
Third Department of Internal Medicine, University of Tokyo Faculty of Medicine, Japan.
J Steroid Biochem Mol Biol. 1993 Apr;45(4):235-8. doi: 10.1016/0960-0760(93)90337-v.
To evaluate the possibility that 5 alpha-dihydro-11-deoxycorticosterone (5 alpha-DH-DOC), a weak mineralocorticoid, is an antagonist of a more potent mineralocorticoid, aldosterone, 0.25 microgram aldosterone was injected into adrenalectomized rats simultaneously with 200-800 micrograms 5 alpha-DH-DOC and urinary Na/K ratio and Na and K excretion were evaluated. Urinary Na/K ratio and Na excretion were significantly lower than those of control rats regardless of whether rats were treated with 0.25 microgram aldosterone alone or 400-800 micrograms 5 alpha-DH-DOC alone. Urinary Na/K ratio and Na excretion of rats given a combination of 0.25 microgram aldosterone plus 400-800 micrograms 5 alpha-DH-DOC were significantly higher than those of rats given 0.25 microgram aldosterone alone. None of the treatment caused significant changes in urinary K excretion. The results demonstrate that 5 alpha-DH-DOC, a weak mineralocorticoid, is an antagonist of the sodium-retaining action of a more potent mineralocorticoid, aldosterone. Progesterone which has weak mineralocorticoid activity is also known as an antagonist of more potent mineralocorticoids. The results of the present study demonstrate further evidence that weak mineralocorticoids may work as antagonists of more potent mineralocorticoids.
为评估弱盐皮质激素5α-二氢-11-脱氧皮质酮（5α-DH-DOC）是否为更强效盐皮质激素醛固酮的拮抗剂，将0.25微克醛固酮与200 - 800微克5α-DH-DOC同时注射到肾上腺切除的大鼠体内，并评估尿钠/钾比值以及钠和钾的排泄情况。无论大鼠单独接受0.25微克醛固酮治疗还是单独接受400 - 800微克5α-DH-DOC治疗，尿钠/钾比值和钠排泄量均显著低于对照大鼠。给予0.25微克醛固酮加400 - 800微克5α-DH-DOC组合的大鼠的尿钠/钾比值和钠排泄量显著高于单独给予0.25微克醛固酮的大鼠。所有处理均未引起尿钾排泄的显著变化。结果表明，弱盐皮质激素5α-DH-DOC是更强效盐皮质激素醛固酮保钠作用的拮抗剂。具有弱盐皮质激素活性的孕酮也被认为是更强效盐皮质激素的拮抗剂。本研究结果进一步证明，弱盐皮质激素可能作为更强效盐皮质激素的拮抗剂发挥作用。
